Bis[μ-5-(2-pyrid­yl)tetra­zolato]-κ3 N 1,N 5:N 2;κ3 N 2:N 1,N 5-bis­[triaqua­zinc(II)] bis­(trifluoro­acetate) monohydrate

Li Zhang

doi:10.1107/S1600536809025112

. 2009 Jul 4;65(Pt 8):m871–m872. doi: 10.1107/S1600536809025112

Bis[μ-5-(2-pyridyl)tetrazolato]-κ³ N ¹,N ⁵:N ²;κ³ N ²:N ¹,N ⁵-bis[triaquazinc(II)] bis(trifluoroacetate) monohydrate

Li Zhang ^a,^*

PMCID: PMC2977136 PMID: 21583337

Abstract

The title compound, [Zn₂(C₆H₄N₅)₂(H₂O)₆](CF₃CO₂)₂·H₂O, was synthesized by hydrothermal reaction of ZnBr₂, CF₃COOH and 2-(2H-tetrazol-5-yl)pyridine. The Zn^II cation is coordinated by one N atom from the 5-(2-pyridyl)tetrazolate anion, two N atoms from another 5-(2-pyridyl)tetrazolate anion and three O atoms from three water molecules in a distorted octahedral geometry. The tetrazole ligands bridge the metal ions of the dimeric structure, and the dimers are located on crystallographic inversion centers. An interstitial solvent water molecule is located on a crystallographic mirror plane, and the CF₃COO⁻ counter-anions are also not coordinated to the metal complex. The F atoms of the anions are disordered with the F atoms statistically distributed over two positions in a 0.56 (3)/0.44 (3) ratio. All the water H atoms are involved in O—H⋯N and O—H⋯O hydrogen bonds with uncoordinated water O atoms, carboxylate O atoms and tetrazole N atoms. The interactions link the molecules into a three-dimensional network.

Related literature

For general background to metal-organic coordination compounds, see: Fu et al. (2007 ▶); Georgiev & MacGillivray (2007 ▶). For the crystal structures of related compounds, see: Zhao et al. (2008 ▶); Fu et al. (2008 ▶).

Experimental

Crystal data

[Zn₂(C₆H₄N₅)₂(H₂O)₆](C₂F₃O₂)₂·H₂O
M _r = 775.18
Orthorhombic,
a = 9.1750 (18) Å
b = 14.722 (3) Å
c = 20.657 (4) Å
V = 2790.3 (10) Å³
Z = 4
Mo Kα radiation
μ = 1.83 mm⁻¹
T = 298 K
0.13 × 0.10 × 0.10 mm

Data collection

Rigaku Mercury2 diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T _min = 0.708, T _max = 0.833
27226 measured reflections
3197 independent reflections
2470 reflections with I > 2σ(I)
R _int = 0.074

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.089
S = 1.12
3197 reflections
253 parameters
251 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.35 e Å⁻³
Δρ_min = −0.49 e Å⁻³

Data collection: CrystalClear (Rigaku, 2005 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809025112/zl2226sup1.cif

e-65-0m871-sup1.cif^{(17.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809025112/zl2226Isup2.hkl

e-65-0m871-Isup2.hkl^{(156.9KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3WB⋯O1W	0.809 (18)	2.03 (2)	2.788 (3)	156 (4)
O1—H1WA⋯O4	0.842 (18)	1.965 (19)	2.800 (3)	171 (4)
O3—H3WA⋯O5ⁱ	0.818 (18)	1.956 (19)	2.771 (3)	174 (4)
O2—H2WB⋯N3ⁱⁱ	0.825 (18)	2.08 (2)	2.856 (3)	156 (4)
O2—H2WA⋯O5ⁱⁱⁱ	0.815 (18)	1.956 (19)	2.769 (3)	175 (4)
O1—H1WB⋯N2ⁱⁱ	0.818 (18)	2.02 (2)	2.821 (3)	165 (4)
O1W—H1W⋯O4^iv	0.809 (18)	2.02 (2)	2.791 (3)	158 (4)

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) .

Acknowledgments

This work was supported by a start-up grant from Southeast University to Professor Ren-Gen Xiong.

supplementary crystallographic information

Comment

The construction of metal-organic coordination compounds has attracted much attention owing to their potential functions, such as permittivity, fluorescence and optical properties (Fu et al., 2007; Georgiev et al., 2007). Tetrazole compounds are a class of ligands excellently suited for the construction of such metal-organic coordination compounds because of the various coordination modes they exhibit towards metal ions (Zhao, et al. 2008; Fu et al., 2008). We report here the crystal structure of one such metal-organic coordination compound, bis[(µ₂-pyridinio-2-(2H-tetrazolato)- κ³N¹,N²:N⁵)-hexa-aqua-di-zinc(II)]di-trifluoroacetate monohydrate.

In the title compound, each Zn^II cation is coordinated by one N atom from a 5-(2-pyridyl)tetrazolate anion, two N,N-chelating N atoms from another 5-(2-pyridyl)tetrazolate anion and three O atoms from three water molecules in a distorted octahedral geometry. The tetrazole groups act as µ₂-bridges to link the Zn^II ions into dimers, which are located on crystallographic inversion centers. An interstitial solvate water molecule is located on a crystallographic mirror plane, and the CF₃COO^- counter anions are also not coordinated to the metal complex. The F atoms of the anions are rotationally disordered with the F atoms statistically distributed over two positions with a 0.56 (3)/0.44 (3) ratio. The pyridine and tetrazole rings are nearly coplanar with each other and are twisted against each other by only 6.31 (1)°. The geometric parameters of the tetrazolate ring are comparable to those in related molecules (Zhao, et al. 2008; Fu et al., 2008).

In the crystal structure, all the aqua H atoms are involved in O—H···N and O—H···O hydrogen bonds with the solvate aqua O (O1W), carboxyl O (O4, O5) and the tetrazole N (N2, N3) atoms. The interactions link the molecules into a three-dimensional network (Table 1 and Fig.2).

Experimental

A mixture of 2-(2H-tetrazol-5-yl)pyridine (0.2 mmol), ZnBr₂ (0.4 mmol), distilled water (1 ml) and CF₃COOH (0.4 ml) was sealed in a glass tube and maintained at 323 K. Pure colorless block-shaped crystals suitable for X-ray analysis were obtained after 3 d, yield 55% based on ligand. Anal. Calcd. for C₁₆ H₂₂ F₆ N₁₀ O₁₁ Zn₂: C, 24.77%; H, 2.84%; N, 18.06%. Found: C, 24.69%; H, 2.79%; N, 17.98%. IR (KBr pellet, cm^-1): 3421 (s), 3075 (w), 1726 (s), 1635 (s), 1610 (s), 1561 (w), 1475 (w), 1432 (w), 1367 (s), 1283 (s), 1257 (s), 1181 (w), 765 (w), 721 (w), 687 (w).